-LRB- CNN -RRB- -- A Miami man who shot and killed his wife during a fight at their home in August and allegedly uploaded a picture of her corpse to his Facebook page told police he was defending himself , officials said .

`` I 'm not a killer , '' Derek Medina said in an August video released Friday by prosecutors . `` I do not feel that I 'm guilty and I feel like this was self-defense . ''

Medina , who has pleaded not guilty to second-degree murder , said he and his wife , Jennifer Alonso , were having an argument in the bedroom when `` she started throwing stuff , objects , towards me , '' such as towels , mascara , creams , boxes and shoes .

`` Anything in the room she could throw at me , '' said Medina , who told police he had been an amateur boxer with a 25-0 record . '' ... I got hit in the face a few times . ''

Medina gave these additional details , as outlined in a Miami-Dade Police Department transcript accompanying the video :

At one point , he pulled a gun on his wife and told her to stop . After further discussion , he put the gun away and Alonso told him she was leaving him . They talked again downstairs , where she unloaded a volley of punches on him . He fetched the gun again . She pulled a knife . He wrestled it out of her hands and put it in a drawer .

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`` She just started throwing punches like crazy . She was like really attacking me , '' he told police . `` Like I was getting out of the way and got hit in the arm and she was like going for my temple . ''

Medina told police that Alonso threatend to kill him with a knife , but he disarmed her . He told police Alonso also said she would have someone kill him . Medina said as the fight continued , he shot his wife `` six to eight times . ''

Medina told police he suffered injuries from his wife 's pushing and punching .

According to authorities , Medina wrote on Facebook , `` Im going to prison or death sentence for killing my wife love you guys miss you guys take care Facebook people you will see me in the news . ''

The gruesome image of Alonso stayed online and was passed along for at least five hours . Facebook was notified of the content and employees removed the picture and disabled the pages of Medina and his slain wife .

An autopsy report released on Thursday said Alonso suffered gunshot wounds to her left forearm . Some of the bullets traveled at a downward angle , with one bullet entering her right chin , lodging in her back at the right side of her ribs .

Gunpowder residue was found on her left hand and forearm , and the right side of her neck and chin . Seven bullets and two bullet fragments were recovered .

Journalist Mayra Cuevas contributed to this report .

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Husband : `` I feel like this was self-defense ''

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Facebook image of wife 's body was online for hours

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`` She just started throwing punches like crazy , '' husband says